Technical Field
The present invention relates to a method for supplying the electric power of a wind park comprising several wind turbines into an electric power supply grid. The present invention moreover relates to a wind park that qualifies for this purpose.
Description of the Related Art
Wind parks are generally known today, and they describe a conglomeration of wind turbines forming a common unit. Such a wind park is defined, in particular, by a point of common coupling (PCC). All wind turbines use such a point of common coupling to supply electric power into the supply grid.
Ideally, the wind turbines—and thus the wind park—will supply as much power into the supply grid as is possible given the prevailing wind conditions. There may be also situations where it may be desirable to reduce the supplied power, for example in the case of a power surplus at the supply grid. On the other hand, it may also make sense to reduce the performance of the wind park below the currently feasible value, for example in anticipation of an increased power demand at the grid, to be able to increase the supplied power as soon as the anticipated high demand occurs suddenly at the grid.
From patent application US 2005 0042098 A1 we know that the grid operator can specify a percentage power value for the wind park, which—in relation to the wind park's nominal powers—specifies a lower, desired power value to be supplied. For example, if the grid operator wants the wind park to supply no more than half of the nominal power, he can specify a value of 50 percent for the wind park. This value is then supplied to the wind turbines, which will reduce their output accordingly. In this way, not more than half of the nominal power is supplied.
A problem may arise, for example, if one wind turbine fails to work. In that case, this failed installation would not provide any power at all. The remaining installations could provide correspondingly more power if they could recognize the failure of that one installation, and if the power level were known by means of which the failure of this one wind turbine could be compensated by the remaining wind turbines. However, such an exchange of information, as well as the coordination of the wind turbines to compensate for such deficiency in output, is complicated. One must also take into account that some wind parks comprise wind turbines with different power output, and sometimes even wind turbines stemming from different manufacturers. Those are called mixed wind parks.
The German Patent and Trademark Office has researched the following prior art in the priority application for this application: DE 10 2009 030 725 A1, DE 10 2011 112 025 A1 and US 2005/0042098 A1.